Conventionally, ice skate blades used for ice hockey have been constructed entirely of steel. In order to obtain the necessary strength and ruggedness these skate blades had fairly thick runners, approximately 0.180 inches. Subsequently, the tube and hollow column construction, known as the tube skate, was developed to reduce weight without reducing the strength or ruggedness of the runner and to allow construction of a thinner runner, approximately 0.120 inches, to increase speed. Improved quality steels and metallurgical processes, welding methods, etc. have made it possible for skate blade manufacturers to continue to improve the all-steel blades over the last few decades.
Subsequently, an attempt was made to further reduce the weight of the hockey skate blade by using a combination of plastic and steel instead of an all-steel construction. Canadian Pat. No. 585,720 was an early example of such construction. However, due to excessive runner breakages, the product was discontinued.
Eventually, a composite assembly, a plastic-steel skate, was introduced and these are now fairly common in the art, several manufacturers marketing a product using a plastic bridge component and a steel runner.
The conventional plastic-steel skate arrangements have achieved the objective of reducing the weight of the assembly as compared to an all-steel hockey skate but the resistance to breakage of the skate runner has been found to be far inferior in conventional plastic-steel skate assemblies when compared to the all-steel skate blades still in use and accordingly the use of the composite blades in present construction presents a hazard to the user and others on the ice surface.
Some examples of conventionally practiced methods of construction in composite skate arrangements are to be found in the following Patents: U.S. Pat. No. 4,131,288 issued Dec. 26, 1978 to Wilson, U.S. Pat. No. 4,071,938 issued Feb. 7, 1978 to Chambers, U.S. Pat. No. 4,074,909 issued Feb. 21, 1978 to Baikie, U.S. Pat. No. 4,093,249 issued June 6, 1978 to Chambers, U.S. Pat. No. 4,088,335 issued May 9, 1978 to Norton et al, U.S. Pat. No. 4,085,944 issued Apr. 25, 1978 to Chambers, U.S. Pat. No. 3,967,832 issued July 6, 1976 to Chambers, U.S. Pat. No. 3,954,278 issued May 4, 1976 to McLeod, U.S. Pat. No. 4,053,168 issued Oct. 11, 1977 to Goverde, Canadian Pat. No. 984,422 issued Feb. 24, 1976 to Baikie, Canadian Pat. No. 985,322 issued Mar. 9, 1976 to Tvengsberg, Canadian Pat. No. 989,436 issued May 18, 1976 to Baikie, Canadian Pat. No. 697,856 issued Nov. 17, 1964 to Fiorjancic et al, Canadian Pat. No. 585,720 issued Oct. 27, 1959 to Kirkpatrick et al.
The above examples of the prior art show various methods of connecting a steel runner to a plastic holder, the holder subsequently being secured to a skate boot. These methods include rivets as shown in the Wilson U.S. Pat. No. 4,131,288 with a portion of the runner being extended up into the columns of the holder. In the Chambers U.S. Pat. No. 4,071,938 the runner shown in FIG. 2 is provided with a plurality of circular apertures through which rivets 45 are subsequently provided to attach the runner to the lower part of the holder. Vertical bolts are used in the U.S. Pat. to Baikie, No. 4,074,909 to detachaby secure the blade to the columns of the holder as shown in FIG. 3 of that Patent.
Of the plastic steel skates now in use none meets the impact or compression tests sustained by the all-steel hockey skate blade. Tests show that they are all substantially inferior in ruggedness. This accounts for the exceedingly high breakage rate. It will be appreciated that when a skate runner breaks and is ejected from the plastic bridge, it assumes the character of a lethal weapon and is a menace to ice hockey players and in some cases to spectators.
In order to reduce the excessive breakage of steel runners, the manufacturers of current plastic blades have reduced the Rockwell hardness of the runners to as low as 50.degree. R.C., the maximum hardness found being 55.degree. R.C. Conversely, the runners of all steel hockey skates are hardened to 58.degree.-60.degree. R.C. As the resistance to wear and therefore the retention of sharpness is directly related to the hardness of the runner it is desirable to have as hard a runner as possible. However, with a hard, brittle runner in the presently manufactured plastic holders, the runner shatters easily due to the lack of holder support. Lowering the hardness of the runners cuts down on the breakage but results in an inferior runner.